1. Technical Field
The present invention relates to a tilt coil mounted in front of a deflection yoke of a cathode-ray tube (hereinafter referred to as "CRT") in order to perform a tilt function and an earth magnetic field compensation function, and more particularly, to an improved tilt coil mounting device of a display which makes the tilt coil fixed around a bulb of the Cathode ray tube at a fixed interval by a tilt fixing member separately provided in order amicably to mount the tilt coil, and fully perform tilt and earth magnetic field compensation functions.
2. Related Art
Generally, a cathode ray tube has a neck portion fitted with a deflection yoke for directing an electron beam to an external circumference in a predetermined direction, and an electron gun for emitting a predetermined electron beam to a predetermined part of internal circumference; a funnel portion formed in front of the deflection yoke; and a panel portion for producing a predetermined image. Early efforts to compensate for deflections produced in a particular cathode ray tube attributable to factors such as idiosyncracies of the structure of the tube and non-linear conditions in deflections circuits included the Magnetic Means For Producing Compensations And Other Effects In A Cathode Ray Tube of N. G. Kabuss, U.S. Pat. No. 2,591,159, relied upon permanent magnets that were adjustably supported on a ring structure encircling the neck of the cathode ray tube, adjacent to the region where electrons pass after being deflected by the normal deflection coil, and the Magnetic Compensator of J. G. Chandler, U.S. Pat. No. 3,106,658, which endeavored to improve color registration using a ferromagnetic yoke encircling a color tube between its deflection system and its color-selection barrier.
The art disclosed by Robert J. Powell in U.S. Pat. No. 5,198,729 for CRT Monitor With Elimination Of Unwanted Time Variable Electric Field, when a cathode ray tube is manufactured the funnel portion of the Cathode ray tube is coated with a conductor, and then a magnetic field is formed by the conductor applied with an electric current, in order to perform tilt or earth magnetic field compensation functions. There have been some problems heretofore that have prevented various kinds of cathode ray tubes from being equipped with a tilt coil in this manner. Therefore, the method of using the tilt coil has been practiced as another means to perform tilt or earth magnetic field compensation functions.
In one technique commonly used in contemporary art, a tilt coil is simply coiled around the bulb portion of the tube in front of the deflection yoke. There are still some problems in this technique however, because a constant tilt function can not be performed due to the irregular coil of the tilt coil coiled on the Cathode ray tube, and that the tilt efficiency deteriorates because of the tilt coil without being fixed in position tends to slant to one side as a result of any impact on the product. In another contemporary technique, a tilt coil is wound around the front side of the deflection yoke. When the tilt coil is integrally coiled with the deflection yoke however, the tilt coil is not properly positioned around the exterior of the Cathode ray tube. As a result, the tilt and earth magnetic field functions are deleteriously compromised. Additionally, because the tilt coil should be coiled after the deflection yoke is formed, mounting of the tilt coil is troublesome and difficult to manufacture.
Dossot, et al., Auxiliary Coil Fastener In A Deflection Yoke, U.S. Pat. No. 5,592,045, advocates an auxiliary deflection coil mounted on a support ahving an opening disposed around the neck of the cathode ray tube, for modifying the main deflection field created by the main deflection coil. A separator is used for mounting the main and auxiliary deflection coils. This type of structure depends upon a plurality of positioning studs and adjustable feet to obtain satisfactory placement of the auxiliary coils.